Streamliner

Sorry to hear about that, Wolf. I wasn't aware that the RFT blow easier than conventionals. Is that right? Just the stiffer sidewall? Is there any sort of road hazard warranty on your tires? If not, what will it cost to replace the tire? Just curious. Good luck with that.

Wolfman

The sidewall stiffness makes it easier to sustain damage (bubbles/sidewall cuts). Now they will install a set on conventional all-season tires (Conti ExtremeDWS 06). Cheaper, longer lasting and better ride quality. We had those on our BMW and were quite satisfied...

No road hazard as I usually swap out tires and/or wheels. The tire normally runs around $350-$400. It certainly had a short life

wows500

I had 19 inch rims on my 2008 S with conventional tires the sidewall height was 4.5 inches. It gave me good service. Now with the 2015 RFT on a 19 inch rim the sidewall width is 4.3 inches a difference of .2 inches and I think it should give me good service also on the 2015.
Regarding the blowouts is it more common on wider rims (20, 21 and up) as compared to 19 inches as I think the wider the rim the thinner the sidewall width gets till it gets to be a rubber band effect?

rusty104

I was reluctant to get the optional 19" wheels due to pot holes but I liked the design of them and thought I would try them. There is no way living in the northeast that I would go for 20" ones. Friends of mine who have 20" non-run flats have all had issues including bent (ruined) rims. I wouldn't be so sure that the cause was the run flat design.

jmrdmd

I'm pleasantly surprised with the ride quality of my 2015 with the 20" Goodyear F1's
Jan

Wolfman

Rim diameter always plays a role but the run flats are designed to carry a 5000 pound car without any air, so the sidewall are extremely thick/strong.

A 20" Run Flat is much stronger than an 18" conventional tire. Which is actually not as good as there is less flexibility to adsorb a hit.

While potholes can take out any tire and rim for that matter, chances are better with a softer, more flexible tire.

Wolfman

We got the car back with a nice set of 20" conventional tires

Instead of the Pirelli P Zero Summer Run flats, we now have Conti Extreme DWS all season tires which we need for our nasty winters. After all, this is our winter car...

What a difference the tires make!!!
Softer, more compliant ride and much quieter. More luxurious and not that
hollow sound as I had with the Pirellis.
I had the same set on the BMW and they actually get more quiet after a 1000 miles or so.

Happy

clembo

Wolf - I changed to those exact tires two months ago. Softer ride than the 20" F1 Runflats that came as OEM on my car.

wows500

[QUOTE=Wolfman;6606502]Rim diameter always plays a role but the run flats are designed to carry a 5000 pound car without any air, so the sidewall are extremely thick/strong.

A 20" Run Flat is much stronger than an 18" conventional tire. Which is actually not as good as there is less flexibility to adsorb a hit.
QUOTE]

Nice to know Thanks

Streamliner

Welcome aboard! Now, if we can just get MB to give us the SPACE to store a compact spare, under the trunk floor, we'll be good to go--anywhere! I cannot believe they cannot accomplish that for the 2018. There is almost enough room under there now. If they just move a few things around, it should be doable. Write a letter--today!

Wolfman

We have removed run flats of every car that has it and it always resulted in a major improvement in ride quality or performance.

I am surprised that so few do this. Run flats diminish the everyday driving experience for what? The potential (or occasional) benefit of having to get the tow truck instead of limping home?

The new BMW 7 series now has the option for a spare even with run flats, but according to a Bimmerfest member, the trunk space is becoming much more shallow with the spare.

MBZFAN55

My 2015 S550 on 19" RFT's is approaching 12k miles and, in my humble opinion, these tires are "just acceptable". The ride is OK, the noise is OK, but I am not a happy Mercedes camper. On prior S-Class models I ran 19" All Season for Fall/Winter months and 20" Performance for Spring/Summer. I just can't bring myself to purchase 20" performance (sic) run flats. Besides the crazy cost of the RFT's, has anyone had the occasion to try to obtain one for replacement? In a previous thread I told my tale of having to contact Continental corporate to get a replacement 19", just a few months after vehicle delivery. The S-Class is supposed to keep me calm & relaxed and instead I am irritated and upset. I would gladly pay extra for conventional tires and the spare/jack kit, if only Mercedes would give back the provision to accommodate the package under the trunk. The trunk on the W222 is smaller than prior models so I am not enthusiastic about losing the remaining trunk space and driving in my urban area without a spare is just not realistic. (I've never had to personally change a tire on the S, but you know what would happen!!). Thanks again for letting me rant.

Streamliner

Yeah, my W221 compact spare sits on top of my 2015 S550 sedan trunk floor. I don't like it, but it's the best I could do. I can still fit two rolling suitcases on top of it and whatever else my wife and I need for a trip to Napa in the remaining trunk space, but it is annoying.
Yesterday, I filled out the MB questionnaire that they sent me regarding my recent service visit. In the "additional comments" area, I mentioned the lack of a jack & spare in my car. I realize it wasn't the right venue, but to me, ANYTIME I get the chance to communicate with ANYONE from MB, whether it be at the dealer level or at MBUSA, I LAUNCH into my disappointment over the lack of a spare, and I strongly suggest that you and everyone else here do the same thing. At some point, we will be heard.

Steinhart

I'm happy with the ride, 20" Goodyear F1 stock RFT's, '15 S550V4

However I don't have anything else to compare it to

I'll probably switch to regular tires when these wear out. MB recommends sealant and portable air pump kit if running regular tires, but I guess a spare would be a better solution....

UAG1

are all the OEM PZero are RF tires?
ride is not bad (always driving AMG or porsche) compare to my other cars.

Wolfman

Yes, they are. They are not bad on excellent roads but harder and noisier over any bumps.

Here in Minneapolis, many highways with concrete pavements have grooves cut into it every couple inches to prevent surface freezing and the sound is extremely annoying with rf's.

happyinva.

To MBZFAN55-Do you have the Conti's or Michelin MXM4's?I have the latter and am getting good wear and ride,minimal noise etc.I have extensive experience with tire drama.Had problems on a 2011 XJL.OEM Pirelli's were crap.Tried Michelin Pilot Sport A/S and Serenity Plus's.Both got real noisy at 15k,despite rotation.Settled on Yoko Advan Sport A/S,but traded for my S after 6k.After all that,I'm happy not to have to deal with it.You must rotate and road force balance.Streamliner loves his Serenity's.

RJC

These seem to best the best RF available on the new S (with the SP and 20's) for noise and ride comfort based upon the cars I've tested and some other comments posted here...hope my coupe has them. Nice to see an American company putting out such a good product and bettering the import offering(s).

MBZFAN55

Thanks for the suggestion but my problem is my undesirable original equipment run flat tires, not the availability of the highly desirable traditional, all season and performance tires.

Streamliner: I took your advice and filled out a MB survey today about a recent dealership visit, and expressed my displeasure at the RFT/no spare tire issue.

Streamliner

Well, that at least makes TWO of us.
Much appreciated.

e55phil

I was very unhappy when my 15 s550 had no spare. I was going to by conventional tires and find a spare to buy.

Because I could not find a spare and kept running the run flats. ( I have the 20 inch multi-spoke for the summer and 19 inch amg wheels with all weather tires for the winter)

The more reading I did on line the better I felt about the run flats. To be honest I would hate to have to change a tire on the side of the road and if I have to wait for Roadside I would rather do it at a diner or truck stop or better yet drive home.

I am sure that the conventional tires handle better than run flats but my S Class is not a race car and in my opinion my S550 with the run flats handles almost as good as my e55 in normal driving and that is good enough for me.

Some would call me stupid but I bought the tire and rim insurance and if you do not run the recommended tires you are not covered.

So I am happy with the run flats and I predict that time makers improve them in the years to come.

MBZFAN55

You may be on to something here. I've done some extensive research and unless MB goes back to the spare tire - very doubtful as more car manufacturers everyday are deleting the oe spare tire - I may just have to accept RFT's as "de rigueur". But as you predict, there may be an improved RFT appearing shortly from Bridgestone. They have come out with a RFT called Drive Guard as a replacement tire and initial reviews are exceptional, particularly for a RFT. Unfortunately the tire is not currently made in the S550 19" or 20" sizes, so for now, no light at the end of the RFT tunnel.

Wolfman

RFT's have been around for 20 some years or so and their ride quality has always been inferior. This is inherent to their thicker sidewall design.

Expecting a luxurious ride quality equal to non-ride flats will be wishful thinking.
It's not that Mercedes suddenly switched to run flats because of some new tire technology; this is strictly done to comply with fuel consumption standards (EU/US). This is why we are cursed with the ECO start/stop as well.

PJ550CAB

Little off topic here, but thought some of you would get a laugh out of this. Was casually checking out the new Fiat 500X for my winter wheels to replace my bland Honda CRV. Not really impressed with the room inside the 500x, walked around, opened the hatch and was told a space saver spare was a $700 option. And no, the car did not come with run flats. Ran out of there.

flint350

I'm 2200 miles in on my 2015 S550 4matic and tomorrow I change over from the OEM Continentals to Serenity Plus. To help with trunk space, I present my new "spair".



It fits fine in the lower trunk space.